(Adds Navy comment, paragraphs 12, 13)
WASHINGTON May 7 (Reuters) - Sikorsky Aircraft, a unit of United Technologies Corp, won an initial $1.24 billion contract to develop and build six new U.S. presidential helicopters, the first step toward a fleet of 21 new aircraft by 2023, the Pentagon announced on Wednesday.
The award capped years of efforts by the U.S. Navy to replace the current fleet of aging Marine One helicopters, also built by Sikorsky, some of which have ferried the president and other top officials since 1974.
Sikorsky has built all presidential helicopters since 1957, when Dwight Eisenhower became the first U.S. president to regularly use helicopters.
Former Defense Secretary Robert Gates canceled an earlier program managed by Lockheed Martin Corp in 2009 after the cost more than doubled to around $13 billion, prompting President Barack Obama to describe it "an example of the procurement process gone amok."
The total value of the new program is expected to be about $3 billion, said Marty Hauser, director of government communications for United Technologies.
Lockheed will be the key subcontractor to Sikorsky on the new program, which is based on the Sikorsky S-92 helicopter that is already used by 10 nations for their head of state missions.
"For 57 years, our company has been trusted with the critical responsibility of building and supporting a safe and reliable helicopter fleet for the president of the United States," Sikorsky President Mick Maurer said in a statement. "We stand ready to deliver the next Marine One, the world's most advanced executive transport helicopter."
Efforts to buy a new presidential helicopter began shortly after the Sept. 11, 2001, hijacking attacks, which revealed the outdated nature of communications systems on the existing fleet.
"I'm glad to see this is finally over," said Mark Rosenker, a retired Air Force general who headed the White House Military Office at the time and initiated the drive to buy new aircraft.
"These aircraft are maintained extremely well, but they need to brought into the 21st century," Rosenker said. He said the previous acquisition got out of hand because of never-ending requirements, but Navy and White House officials now realized "they don't have to have every bell and whistle."
Since 2004, Sikorsky has delivered more than 200 S-92 helicopters, mainly to companies in the oil and gas industry, and for use by civilian agencies for search and rescue.
Sikorsky was the sole bidder for the helicopter after other companies decided not to compete. Navy Captain Dean Peters, who heads the program for the Navy, said the contract was on fixed-price terms, with an incentive fee. He said the goal was to integrate mature equipment into an existing, in-production aircraft to minimize development and testing costs.
He said Sikorsky would build six test aircraft, of which four would later be used for operations. The contract will have options for 17 additional operational aircraft, the Navy said.
Connecticut lawmakers Representatives Rosa DeLauro and John Larsen said the news would benefit Connecticut workers.
"Sikorsky has long been synonymous with Marine One, the presidential helicopter," DeLauro said. "Every president since Eisenhower has flown in a Sikorsky, made right in Connecticut." (Reporting by Andrea Shalal; Editing by Sandra Maler, Tom Brown and David Gregorio)